GC-MS-based PAHs, C2-DBF and hopane ratio in the uppermost Permian Changxing Fm. in the Meishan C section

The non-polar fraction of toluene:MeOH (9:1) extracted sediment samples was analyzed by GC-MS on an Agilent gas chromatograph (GC, 6890) interfaced with an Agilent 5975 mass selective detection (MSD) instrument. A DB-5MS column (60 m × 250 μm × 0.25 μm) was installed with the GC oven. The temperature program was: isothermally at 40 °C for 2 min, ramped to 320 °C at a rate of 4°/min, and then held at this temperature for 22 min.